Transmitting-telephone



(No Model.)

T. A, EDISON.

TRANSMITTING TELEPHONE.

No. 274,576. Patented Mar.27,1888.

N. PETERS. Pvweoulha nplm, Wnh n tm D11 UNITED STATES PATENT FMCETRANSMITTING-TELEPHONE.

SE'EGIFIGATION forming part of Letters Patent No. 274,576, dated March.27, 1883.

Application filed October 6, 1882. (No model.)

To all whom it may concern Be it known that I, THOMAS ALVA Emson, ofMenlo Park, in the State of New Jersey, have invented an Improvement inTransmitting-Telephones, (Case No.159 of which the following is aspecification.

This application is a division of my application filed November 18,1878, No. 159, and said division is made for the purpose of separatingfrom the said original application the different features of inventioninto three additional applications. The present 1 term Case No. 159

In my application No. 130, heretofore filed, the circuit passes throughplumbago or similar material, and the diaphragm that is acted upon bythe sound-waves serves to vary the electric tension by the extent ofsurface contact.

In my Case No. 151, patented April 30, 1878, No. 203,016, I have shownan induction-coil with primary and secondary circuits and receiving andtransmitting telephones. A carbon button in a circuit and acted upon bythe diaphragm is shown in my said (Jase 151 and also in Case 141. Theseare not therefore claimed herein.

In my present improvement 1 make use of a surface or surfaces havingnumerous points produced by scores or fine linesacross the surface,preferably about at right angles to each other, and this surface orsurfaces are in the electric circuit and combined with the diaphragm, sothat the movement given to the diaphragm by the sound-waves will producegreater or less intimacy of contact at the scored surface and aconsequent rise and fall of electric tension. I also combine with abutton of carbon or equivalent material in one circuit an electro-magnetin another circuit, the armature of which varies the pressure upon suchcarbon or other finely-divided, material, and by this means repeats thetelephonic pulsations. I also construct the telephonic receiver in apeculiar manner to prevent injury by undue currents, such as fromlightning, and so that the diaphragms and cores will be polarized byinduction, and the line-current will act in two helices to vary themagnetism.

In the drawings, the diagram Figure 1 represents the transmitting,receiving, and repeating instruments, the instruments at X being at onestation and the instruments at G being at the repeatin g-station. Fi g.2 is a detached view of amodification of the repeating- 5 5 instrument,and Fig. 3 is a face view of the tension-regulator. formed by a surfacescored' with numerous lines.

The telephonic transmitter A is made with against which the sound actsto vibrate the same. i

The plate a is in the bottom of a vulcani te cup or holder, 20, and canbe adjusted nearer to or farther from the diaphragm c by the 6 screw 21.

The tension'regulating device ,1 is between the plate 6 and the secondplate, a, the wires 10 and 12 of the circuit to the battery B connecting, so that the circuit passes through 76 these plates andtheintervening tension-regulator. The tension-regulating device iscomposed of two contiguous surfaces, one or both of which are scoredwith numerous fine lines,s0 as to produce a great number ofcontact-points. 5 By adjusting the screw 2i the initial pressure can beregulated, and. the vibrations of the diaphragm due to the action ofsounds will vary the pressure and the extent of surface contact, so asto produce rise and fall of tension in the circuit by bringing more orless of the points on the surface or surfaces into contact.

In Fig. 3 I have shown the surface scored as aforesaid, and it is to beunderstood that 8 the scoring is to be of the requisite fineness,preferably several thousand to the inch.

In the instrument A, Fig. l, the tension-reg ulatoris composed of astrip of platina scored by lines of ruling at right angles, and folded,9c with a piece of felt, rubber, or similar material within the fold,and the scored surfaces in contact with the'plates a and 6,respectively. Several layers of foil ruled as aforesaid may be placedtogether, if desired, to obtain great re- 9. 'sistance and variation inthe electric tension of. the circuit. The foil ruled as aforesaid isbelieved to operate in the circuit in a similar manner to acarbonbutton. Between the diaphragm c and plate a there is a short section Iof a tube, 6, to form a central hearing.

The inductorium I has its primary included a case containing thediaphragm or plate 0, 6o

in the circuit to the battery B and tensionregulator and its secondaryto the line and ground. The receiving-telephone R is placed in theline-circuit passingthrough the secondary of the inductorinm. At thereceivinginstrument B there is a permanent magnet, H, and upon one polethere is a bar, 23, forming at its ends the cores for the helices 3 and4, that are in the line-circuit; and upon the other pole of the magnet Hthere is a bar, 24, that is connected at its ends to the diaphragms d I.These diaphragms hence are polarized by induction, and are of onepolarity-say south- While the cores 3 and 4 are polarized north byinduction. Flexible tubes m, with ear-pieces, are connected to thechambers or cases holding the diaphragms d (1, so that the sound isconveyed to the cars. This apparatus is not liable to becomedemagnetized, because any currentwhich passes through the helices 3 and4 acts to increase the induced magnetism at one end of the bar 23 inproportion as it tends to decrease the induced magnetism in the otherend. Thus there will be no tendency to injure the permanent magnet H;but the telephonic current will cause the diaphragms to respond by thechange of magnetism in the cores adjacent to the diaphragms.

The repeating-instrument at the station" G contains an electro-magnet, Bthe helix of which is in the main-line circuit. Its core is adjacent toan iron plate or armature, andthe variation of the magnetism resultingfrom the action of the current in the main line increases and decreasesthe pressure upon a button of carbon, 9, or similar material forming thetension-regulator in a second electric circuit. I have shown the localcircuit from the battery B as passing to the platef at one side of thecircuit-regulator g and to the adjusting device of the plate It at theother side of the carbon or similar material; and in this local circuitis the primary ofthe indnctorium 1 the second ary of which is in theline P, to the distant receiving-instrument. I prefer to connect thecore of the electro-magnet B to one pole of the permanent magnet A, sothat it may be polarized by induction, and hence the line-current willincrease or decrease the magnetism of the core of B The armature-plateof the magnet B is shown upon a lever, 0, having a fulcrum at 0, and thespring at (1 which should be adjustable, serves to apply an initialpressure to the tension-regulator g, and I prefer to use a shortcylinder, 6,'between the armatureplate and the disk f, to insure acentral bearing on the tension-regulator. When an electric wave from thedistant station varies the power of the magnet B the pressure upon thetension-regulator g is decreased or increased, and the primary currentfrom B acts in the inductorium to translate or reproduce on the secondline, 1?, currents corresponding or proportionate to those sent from theinstrument A. The receiving-telephone, being in the main line, respondsto the electric waves transmitted by the inductoriu'm as the resistancein the primaryof the inductorium is varied by the that act as atension-regulator for the trans lating or repeating circuit that passesthrough the lever S and diaphragm C hence the rise and fall of electrictension in the repeatingcircuit will result from the vibrations of thediaphragm, producing moreor less pressure and intimacy of contact in thetension-regulator at 14 15, the initial pressure being determined by theproximity of the magnet H to the lever S. 7

It will be observed that in my telephone-instruments I provide anelectric tension-regulator having an extended surface, incontradistinction to a point or small hearing such as shown in myapplication No. 141, and instead of the electric tension -regulatorcoming directly into contact with the diaphragm, as in my .applicationNo. 130, I combine with the electric tensionrregulating device anintermediate bearing having a small contact with the diaphragm and therequired extent of surface against the tension-regulator. T'nis bearingis non-elastic to transfer more positively to the tension-regulator thetremulous movements of the diaphragm, as distinguished from the yieldingmaterial, such as cork or rubber, as shown in myPatentNo.203,0l6. If thecurrent passes through this non-elastic bearing-piece, as at A, the sameis to be of metal or other good conductor.

Certain of the'devices shown herein are not claimed, as they form thesubject of other applications. I claim as my invention-- 1. In atelephonic transmitter, the combina tion, with the diaphragm, of one ormore metallic plates the surface or surfaces of which are scored withnumerous fine lines to form a tension-regulator in an electric circuit,substantially asset forth.

2. In a telephonic transmitter, the combina tion, with the diaphragm andthe electric circuit, of. two contiguous surfaces, one of which isscored with numerous fine lines to form a tension-regulator,substantially as set forth.

3. The combination, with the diaphragm in a telephonic transmitter, of atension-regulator, a metallic surface at each side of the same, and acentral bearing between the dia phragm and one of the metallic surfacesthat inclose the tension-regulator, substantially as set forth.

4. In a speaking-telephone, the combination, with the diaphragm and thetension-regulator,

vice to regulate the initial pressure upon the tension-regulator andagainst the diaphragm, substantially as set forth.

7. The combination, in a telephone-instrw ment, of a diaphragm the edgesof which are clamped in a case and a mouth-piece, a tensionregulator, acup or recess for the same, a nonelastic plate between the tensionregulator and the diaphragm, and a non-elastic bearing against saiddiaphragm, substantially as set forth.

THOMAS A. EDISON.

Witnesses Gno. T. PINGKNEY, HAROLD SERRELL.

Signed by me this 30th day of March, A. D. 5

